Well, it depends on how the destination mail server is configured... but nowadays that's really rare so I will agree with SpikeZ... No

system
—
2013-02-10T03:03:12Z —
#4

I guess it's not. I've tried it and I can still access my email.

Cusion1991
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2013-02-10T12:42:56Z —
#5

I don't think it would really matter if you typed your email addy using upper or lower case. Passwords are the ones that are case sensitive.

Stomme_poes
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2013-02-10T21:50:07Z —
#6

The mail servers determine this.

According to the RFC, this should be a valid email address=^.^=@kitteh.cat

But no server I know of will accept this.

Jackp15
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2013-02-11T15:42:27Z —
#7

No, it's not case sensitive, but I think it should be because it will almost close bulk email services problems

winagain
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2013-02-11T18:45:44Z —
#8

It's better if is not case sensitive. Imagine all the problems it would cause. For starters, you would have thousands of variations given a name: name@hotmail.com, Name@, nAme, nAmE etc. etc.

Stomme_poes
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2013-02-11T19:48:52Z —
#9

winagain said:

Imagine all the problems it would cause.

Like all the problems you get on any Unix filesystem?

I like case sensitivity, but Windows has trained most users to ignore it.

felgall
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2013-02-11T21:16:54Z —
#10

Stomme_poes said:

The mail servers determine this.

According to the RFC, this should be a valid email address=^.^=@kitteh.cat

But no server I know of will accept this.

Have you tried specifying it as:

"=^.^="@kitteh.cat

any string of up to 255 characters is meant to be acceptable before the @ provided it is enclosed in "". Of course the one you specified is valid even without the quotes.

Perhaps more people need to look at using a proper email address parser such as http://code.iamcal.com/php/rfc822/ for PHP, ruby and python so that they can properly recognise what is and isn't a valid email address.